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<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
        function demo(num) {
            console.log(111,num)
            // 1.定义变量，这时打印的还是10
            var num = 20;

            console.log(222,num)
            // 2.声明函数：这时打印的是对象
            function num() {
                console.log(111)
            }
            
            // var num = 20;
            console.log(333,num)
        }

        demo(10);
    </script>
</body>
</html>